I am seeing repeated problems with misconfigured systems that have shared IRQdevices configured for edge-triggered. Also, network devices using NAPI won'twork reliably on edge-triggered IRQ's. The kernel IRQ architecture doesn'thave sufficient information to detect this at boot time. We should fail request_irq() if the SA_SHIRQ but the irq is edge-triggered.

Right now the concept of level vs edge triggered is buried in things like ELCR for oldPIC, and other stuff for IO-APIC. There is a IRQ_LEVEL flag in the descriptor fieldbut nothing sets it or uses it.

Haven't even looked at non i386 arch's but probably even more confusion there.